In the past a number of studies have shown that perfusing the anterior chamber of an eye with mock aqueous humor solution resulted in an increase of the outflow facility. This has been called the "wash out" phenomenon. This effect was not observed when pooled aqueous humor was used as the perfusing fluid. It has been postulated that the "wash out" phenomenon is due to the slow removal of glycoso-aminoglycans, in particular hyaluronidase sensitive ones, from the trabecular meshwork. The aqueous humor, therefore, contains a substance which is responsible for the integrity of the outflow resistance. The hypothesis to be tested is that this substance is a hyaluronidase inhibor. A hyaluronic acit - hyaluronidase assay will be set up and aqueous humor withdrawn at the time of glaucoma operations will be tested to ascertain if an abnormal amount of such an inhibitor is the underlying cause of intracular pressure elevation in Open Angle Glaucoma. Human aqueous humor from cataract operations will be used as control. The anterior chamber of Rabbit Eye will be perfused in vivo to test the ability of different compouonds (i.e. hyaluronidase inhibitors) in preventing the "wash out" phenomenon. Column chromatography and elecrophoresis will be performed on pooled aqueous humor to isolate the fraction responsible for the maintenance of outflow resistance. The different fractions will be tested in the anterior chamber perfusion experiments and in athe hyaluronidase inhibitor assay. Once this compound is isolated and characterized it will be possible to modulate its effect on the trabecular meshwork to induce a "wash out" phenomenon therapeutically in patients with glaucoma. Understanding how the trabecular meshwork maintains its integrity could help us to find a better way in lowering intraocular pressure in glaucoma. This grant application is in response to NAEC's Vision Research, A National Plan: page 296 #12.